Albert Barnes Commentary Ecclesiastes 5:18

"Behold, that which I have seen to be good and to be comely is for one to eat and to drink, and to enjoy good in all his labor, wherein he laboreth under the sun, all the days of his life which God hath given him: for this is his portion." — Ecclesiastes 5:18 (ASV)

Rather, Behold what I have seen to be good, it is pleasant for a man to eat. Such thankful enjoyment is inculcated by the Law (Deuteronomy 12:7, Deuteronomy 12:18).